In a silver halide photographic light-sensitive material (hereinafter sometimes referred to simply as “light-sensitive material”) for subtractive color photography, a color image is formed by dyes of three primary colors of yellow, magenta and cyan. In the color photography that uses a current p-phenylenediamine color-developing agent, an acylacetoanilide-type compound is used as a yellow coupler. However, the hue of the yellow dye obtained from these yellow couplers is tinted with red, due to inferior sharpness at the foot portion of a peak in interest of the absorption curve at the longer wavelength side (that is, on the absorption curve, the peak in interest has subsidiary absorption at its foot portion at the longer wavelength side), which renders it difficult to obtain a yellow hue of high purity. Further, there is the problem that, due to the low molecular extinction coefficient of said yellow dyes, large amounts of both the coupler and silver halide are needed to obtain a desired colored density. Therefore, sometimes it results in increasing film thickness of the light-sensitive material, and this consequently reduces the sharpness of the obtained color image. Further, the above-mentioned yellow dyes, which are easily decomposed under the conditions of high temperature and high humidity, or the condition of light irradiation, have insufficient image stability after development processing. Consequently, improvement of these problems is desired.
In order to solve such the problems, the acyl group and the anilido group were improved. Recently, as improved couplers of the conventional acylacetoanilide-series, there are proposed, for example, 1-alkylcyclopropanecarbonyl acetoanilide-series compounds, described in JP-A-4-218042 (“JP-A” means unexamined published Japanese patent application); cyclomalonic acid diamide-type couplers, described in JP-A-5-11416; pyrrole-2- or 3-yl- or indole-2- or 3-yl-carbonylacetoanilide-series couplers, described in, for example, European Patent Nos. 953870A1, 953871A1, 953872A1, 953873A1, 953874A1 and 953875A1. The dyes formed from these couplers were improved in terms of both hue and molecular extinction coefficient, compared with the conventional ones. However, they are still deficient in image stability. Further, owing to their complicated chemical structure, the synthesis route became longer, and consequently cost of the couplers became higher, causing a practical problem.
In addition, U.S. Pat. No. 3,841,880, JP-A-52-82423 and JP-A-2-28645 propose acetate ester-series and acetoanilide-series couplers to which 1,2,4-benzothiadiazine-1,1-dioxide is bonded. However, these couplers are low in color-forming property, they are insufficient in molecular extinction coefficient of a resultant dye, and they are inferior in sharpness at the foot portion of a peak in interest of the absorption curve at the longer wavelength side. Therefore, improvement of these problems is desired.
Further, JP-A-58-111943 discloses a blocked magenta-dye-forming coupler. In JP-A-58-11943, there is described the magenta-dye-forming coupler which has a partial structure of acetanilide in which 1,2,4-benzothiadiazine-1,1-dioxide bonds to the blocking group of the coupler. However, said partial structure is just a blocking group. Since the blocking group moiety flows out from a light-sensitive material during development processing, the coupler having the partial structure is not used as an image dye.
Further, JP-A-4-78582 discloses a particular acetanilide-series azomethine dye, to which 1,2,4-benzothiadiazine-1,1-dioxide bonds, and which dye is used as a dye for a thermal transfer recording material. However, the dye is not satisfactory because of such problems that the image obtained from the dye is apt to be ambiguity and it is low in sharpness. In addition, neither fastness nor hue in view of sharpness at the foot portion of a peak in interest of the absorption curve at the longer wavelength side are sufficient.